Systems and methods for forming data storage devices

ABSTRACT

Systems for assembling wafer stacks are provided. An embodiment of the system includes a vacuum chamber, a media deposition component and a wafer stack assembly component. The media deposition component is arranged within the vacuum chamber and is configured to deposit storage media upon a first wafer. The wafer stack assembly component also is arranged within the vacuum chamber. The wafer stack assembly component is configured to align the first wafer and a second wafer relative to each other and bond the first wafer and the second wafer together while at least a portion of the vacuum chamber is maintained under vacuum pressure. So configured, the interior chamber of the wafer stack can be formed as well as maintained under vacuum pressure. Methods also are provided.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention generally relates to semiconductorfabrication. More specifically, the invention relates to systems andmethods for forming data storage devices incorporating semiconductorwafers.

[0003] 2. Description of the Related Art

[0004] Data storage devices that use atomic resolution storage (ARS)techniques for storing data can be formed of multiple wafers that arebonded together as a wafer stack. Such a wafer stack can be diced toform one or more data storage devices. Each data storage devicetypically includes multiple electron emitters and corresponding storageareas that are configured to store data.

[0005] Contamination of one or more surfaces of the various wafers of awafer stack may degrade performance of data storage devices formed fromthat wafer stack. In particular, if some of the interior chambers of thewafer stack become contaminated, the performance of one or more of theemitters can be affected. This can inhibit the ability of a data storagedevice to store and/or retrieve data. Therefore, there is a need forimproved systems and methods that address these and/or othershortcomings of the prior art.

SUMMARY OF THE INVENTION

[0006] Briefly described, the invention relates to semiconductorfabrication. In this regard, embodiments of the invention may beconstrued as providing systems for assembling wafer stacks. Some ofthese wafer stacks can be adapted to form one or more data storagedevices, such a data storage device implementing atomic resolutionstorage techniques. A representative wafer stack includes a first waferand a second wafer, with the first wafer and second wafer definingtherebetween an interior chamber.

[0007] An embodiment of the system includes a vacuum chamber, a mediadeposition component and a wafer stack assembly component. The mediadeposition component is arranged within the vacuum chamber and isconfigured to deposit storage media upon the first wafer. The waferstack assembly component also is arranged within the vacuum chamber. Thewafer stack assembly component is configured to align the first waferand a second wafer relative to each other and bond the first wafer andthe second wafer together while at least a portion of the vacuum chamberis maintained under vacuum pressure. So configured, the interior chamberof the wafer stack can be formed as well as maintained under vacuumpressure.

[0008] Other embodiments of the invention may be construed as providingmethods for forming data storage devices. A representative methodincludes: providing a first wafer and a second wafer, with the firstwafer and second wafer being configured to define therebetween aninterior chamber; maintaining the first wafer under vacuum pressure fora predetermined interval; depositing storage media upon the first wafer;removing contaminants from a vicinity of the first wafer; and bondingthe first wafer and the second wafer together to form a wafer stack sothat the interior chamber is maintained under vacuum pressure after thefirst wafer and second wafer are bonded together.

[0009] Other systems, methods, features, and advantages of the presentinvention will be or become apparent to one with skill in the art uponexamination of the following drawings and detailed description. It isintended that all such additional systems, methods, features, andadvantages be included within this description, be within the scope ofthe present invention, and be protected by the accompanying claims.

DESCRIPTION OF THE DRAWINGS

[0010] The invention can be better understood with reference to thefollowing drawings. The components in the drawings are not necessarilyto scale, emphasis instead being placed upon clearly illustrating theprinciples of the present invention.

[0011]FIG. 1 is a schematic diagram depicting an embodiment of thevacuum assembly system of the present invention.

[0012]FIG. 2 is a schematic, side view of a representative data storagedevice.

[0013]FIG. 3 is a schematic, cross-sectional view of the data storagedevice of FIG. 2 taken along line 3-3.

[0014]FIG. 4 is a schematic, cross-sectional view of the data storagedevice of FIGS. 2 and 3 taken along line 4-4.

[0015]FIG. 5 is a partially cut-away, schematic view of a storage mediumof the data storage device shown in FIGS. 2-4.

[0016]FIG. 6 is a schematic view of a representative reading/writingoperation for the data storage device of FIGS. 2-5.

[0017]FIG. 7 is a schematic view of a representative reading/writingoperation for the data storage device of FIGS. 2-5.

[0018]FIG. 8 is a schematic view of a storage medium of a representativedata storage device.

[0019]FIG. 9 is a partially cut-away, schematic view of the storagemedium of FIG. 8 showing detail of a representative contact layout.

[0020]FIG. 10 is a schematic diagram depicting an embodiment of thevacuum chamber of FIG. 1, showing detail of representative chambercomponents.

[0021]FIG. 11 is a schematic diagram of an embodiment of the vacuumchamber of FIG. 1, showing detail of a representative control system.

[0022]FIG. 12 is a schematic diagram of a computer or processed-basedsystem that may be used to implement the control system of FIG. 11.

[0023]FIG. 13 is a flowchart depicting functionality of an embodiment ofthe control system of FIG. 12.

DETAILED DESCRIPTION

[0024] Reference will now be made to the drawings, wherein likereference numerals indicate corresponding parts throughout the severalviews. As described in greater detail hereinafter, vacuum assemblysystems of the present invention are adapted to enable formation andassembly of wafer stacks. In particular, these wafer stacks can beprocessed, such as by dicing, to form data storage devices, e.g., datastorage devices that implement atomic resolution storage (ARS)techniques for storing data. By assembling the wafers of the wafer stackusing a vacuum assembly system, contamination of the various wafers ofthe wafer stack can be reduced. This can result in the formation of datastorage devices that are substantially free of contaminants and, thus,may exhibit improved performance.

[0025] As shown in FIG. 1, an embodiment of a vacuum assembly system 10includes a vacuum chamber 100. Vacuum chamber 100 defines multiplezones, such as wafer formation zone 102 and wafer stack assembly zone104. Vacuum chamber 100 facilitates assembly of a wafer stack that canbe formed, at least partially, under vacuum pressure maintained withinthe vacuum chamber. For example, the vacuum chamber may provide ahigh-intensity vacuum, i.e., a vacuum of approximately 10⁻⁸ Torr. Asdescribed in greater detail hereinafter, the wafers of a wafer stackdefine one or more interior chambers that can be maintained in vacuum.

[0026] Referring now to FIGS. 2 through 9, a representative data storagedevice 200 employing ARS tech technology is presented. It is noted thatdata storage device 200 is similar in construction to that described inU.S. Pat. No. 5,557,596, which is Incorporated by reference herein.

[0027] As indicated in FIGS. 2-4, data storage device 200 generallyincludes an outer casing 202 that defines an interior space 204. By wayof example, the casing 202 can include walls 206 that define theinterior space. Typically, walls 206 are sealed to each other so that avacuum can be maintained within the interior space. For instance, avacuum of at least approximately 10⁻³ Torr is maintained within theinterior space in some embodiments. Although a particular configurationis shown for the casing 202, it is to be understood that the casing cantake many different forms that would be readily apparent to personshaving ordinary skill in the art.

[0028] Within interior space 204 are electron emitters 208 that face astorage medium 210. These electron emitters can, for example, includefield (i.e., tip) emitters, such as described in U.S. Pat. No.5,557,596. Alternatively, the electron emitters 208 can include flatemitters, such as those described in U.S. patent application Ser. No.09/836,124 (HP Docket No. 10006168-1), filed Apr. 16, 2001, which isincorporated by reference herein. Various other emitters also can beused.

[0029] As described in relation to FIG. 5, storage medium 210 includes aplurality of storage areas (not visible in FIGS. 2-4). In a preferredembodiment, each storage area of the storage medium 210 is configured tostore one or bits more of data. Electron emitters 208 are configured toemit electron beam currents toward the storage areas of storage medium210 when a predetermined potential difference is applied to the electronemitters. Depending upon the distance between the emitters and thestorage medium, the type of emitters, and the spot size (i.e., bit size)required, electron optics may be useful in focusing the electron beams.Voltage also can be applied to the storage medium to accelerate theemitted electrons to aid in focusing the emitted electrons.

[0030] Each electron emitter 208 can serve multiple storage areas ofstorage medium 210. To facilitate alignment between each electronemitter 208 and an associated storage area, the electron emitters andstorage medium can be moved relative to each other, such as in the X andY directions noted in FIG. 2. To provide for this relative movement,data storage device 200 can include a micromover 212 that scans thestorage medium 210 with respect to the electron emitters 208. Asindicated in FIGS. 2 and 4, micromover 212 can include a rotor 214connected to the storage medium 210, a stator 216 that faces the rotor,and one or more springs 218 that are positioned to the sides of thestorage medium. As is known in the art, displacement of the rotor 214,and thereby the storage medium 210, can be initiated by the applicationof appropriate potentials to electrodes 217 of the stator 216 so as tocreate a field that displaces the rotor 214 in a desired manner.

[0031] When micromover 212 is displaced, the micromover scans thestorage medium 210 to different locations within the X-Y plane so thateach emitter 208 can be positioned above a particular storage area. Apreferred micromover 212 preferably has sufficient range and resolutionto position the storage areas 210 under the electron emitters 208 withhigh accuracy. By way of example, the micromover 212 can be fabricatedthrough semiconductor microfabrication processes. Although relativemovement between electron emitters 208 and storage medium 210 has beendescribed as being accomplished through displacement of the storagemedium, it will be understood that such relative movement canalternatively be obtained by displacing the electron emitters or bydisplacing both the electron emitters and the storage medium. Moreover,although a particular micromover 212 is shown and described herein, itwill be appreciated by persons having ordinary skill in the art thatalternative moving means could be employed to obtain such relativemovement.

[0032] Alignment of an emitted beam and storage area can be furtherfacilitated with deflectors (not shown). By way of example, the electronbeams can be rastered over the surface of storage medium 210 by eitherelectrostatically or electromagnetically deflecting them, as through useof electrostatic and/or electromagnetic deflectors positioned adjacentthe emitters 208. Many different approaches to deflect electron beamscan be found in literature on scanning electron microscopy (SEM), forexample.

[0033] Electron emitters 208 are responsible for reading and writinginformation on the storage areas of the storage medium with the electronbeams they produce. Therefore, electron emitters 208 preferably produceelectron beams that are narrow enough to achieve the desired bit densityfor the storage medium 210 and provide the different power intensitiesneeded for reading from and writing to the medium.

[0034] As indicated in FIGS. 2 and 3, data storage device 200 includesone or more supports 220 that support the storage medium 210 within theinterior space 204. When provided, supports 220 typically are configuredas thin-walled microfabricated beams that flex when storage medium 210is displaced in the X and/or Y directions. It should be noted thatvarious combinations of supports and/or springs can be used. As isfurther indicated in FIGS. 2 and 3, supports 220 each can be connectedto the walls 206 of the casing 202 or, alternatively, to stator 216.

[0035] In a preferred embodiment, electron emitters 208 are containedwithin a two-dimensional array of emitters. By way of example, an arrayof 100×100 electron emitters 208 can be provided with an emitter pitchof approximately 5 to 100 micrometers in both the X and Y directions. Asdiscussed above, each emitter 208 typically is used to access aplurality of storage areas of the storage medium 210. FIG. 5schematically depicts a representative embodiment of this relationship.In particular, FIG. 5 illustrates a single electron emitter 208positioned above a plurality of storage areas 500 of the storage medium210.

[0036] As indicated in FIG. 5, the storage areas 500, like the electronemitters 208, are contained in a two-dimensional array. In particular,storage areas 500 are arranged in separate rows 502 and columns 504 onthe surface of the storage medium 210. In a preferred embodiment, eachemitter 208 is only responsible for a portion of the entire length of apredetermined numbers of rows 502. Accordingly, each emitter 208normally can access a matrix of storage areas 500 of particular rows 502and columns 504. However, since each data cluster typically is connectedto a single external circuit, only one emitter of a data cluster is usedat a time.

[0037] To address a storage area 500, micromover 212 is activated todisplace storage medium 210 (and/or electron emitters 208) to align thestorage area with a particular electron emitter. Typically, each emitter208 can access tens of thousands to hundreds of millions of storageareas 500 in this manner. Storage medium 210 can have a periodicity ofapproximately 5 to 100 nanometers between any two storage areas 500, andthe range of micromover 212 can be approximately 15 micrometers. As willbe appreciated by persons having ordinary skill in the art, each of theelectron emitters can be addressed simultaneously or in a multiplexedmanner. A parallel-accessing scheme can be used to significantlyincrease the data rate of storage device 200.

[0038] Writing information to data storage device 200 is accomplished bytemporarily increasing the power density of an electron beam produced byan electron emitter 208 to modify the surface state of a storage area500 of storage medium 210. For instance, the modified state canrepresent a “1” bit, while the unmodified state can represent a “0” bit.Moreover, the storage areas can be modified to different degrees torepresent more than two bit types, if desired. In a preferredembodiment, storage medium 210 is constructed of a material whosestructural state can be changed from crystalline to amorphous byelectron beams. Example materials are germanium telluride (GeTe) andternary alloys based on GeTe. To change from the amorphous to thecrystalline state, the beam power density can be increased and thenslowly decreased. This increase/decrease heats the amorphous area andthen slowly cools it so that the area has time to anneal into itscrystalline state. To change from the crystalline to amorphous state,the beam power density is increased to a high level and then rapidlyreduced. Although temporary modification of the storage medium 210 isdescribed herein, it will be understood that permanent modification ispossible where write-once-read-many (WORM) functionality is desired.

[0039] Reading is accomplished by observing the effect of the electronbeam on storage area 500, or the effect of the storage area on theelectron beam. During reading, the power density of the electron beam iskept low enough so that no further writing occurs. In a first readingapproach, reading is accomplished by collecting the secondary and/orbackscattered electrons when an electron beam with a relatively low(i.e., lower than that needed to write) power density is applied tostorage medium 210. In that the amorphous state has a differentsecondary electron emission coefficient (SEEC) and backscatteredelectron coefficient (BEC) than the crystalline state, a differentnumber of secondary and backscattered electrons are emitted from astorage area 500 when bombarded with a “read” electron beam. Bymeasuring the number of secondary and backscattered electrons, the stateof storage area 206 can be determined.

[0040]FIG. 6 illustrates a representative apparatus for reading in themanner described above. More particularly, FIG. 6 schematicallyillustrates electron emitters 208 reading from storage areas 600 and 602of storage medium 210. In FIG. 6, the state of storage area 600 has notbeen modified, while the state of storage area 602 has been modified.When a beam 604 of electrons bombard the storage areas 600 and 602, boththe secondary electrons and backscattered electrons are collected byelectron collectors 606. As will be appreciated by persons havingordinary skill in the art, modified storage area 500 will produce adifferent number of secondary electrons and backscattered electrons ascompared to unmodified storage area 602. The number may be greater orlesser depending upon the type of material and the type of modificationmade. By monitoring the magnitude of the signal current collected by theelectron collectors 606, the state of and, in turn, the bit stored inthe storage areas 600 and 602 can be identified.

[0041] In another embodiment, a diode structure is used to determine thestate of the storage areas 500. According to this approach, storagemedium 210 is configured as a diode which can, for example, includes ap-n junction, a Schottky, barrier, or substantially any other type ofelectronic valve. FIG. 7 illustrates a representative example of such astorage medium 210. It will be understood that alternative diodearrangements (such as those shown in U.S. Pat. No. 5,557,596) arefeasible.

[0042] As indicated in this FIG. 7, storage medium 210 is arranged as adiode that includes two layers, e.g., layers 600 and 602. By way ofexample, one of the layers is p type and the other is n type. Storagemedium 210 is connected to an external circuit 704 that reverse-biasesthe storage medium. With this arrangement, bits are stored by locallymodifying storage medium 210 in such a way that the collectionefficiency for minority carriers generated by a modified region 708 isdifferent than that of an unmodified region 706. The collectionefficiency for minority carriers can be defined as the fraction ofminority carriers generated by the instant electrons that are sweptacross a diode junction 710 of storage medium 210 when the medium isbiased by the external circuit 604 to cause a signal current 712 to flowthrough the external circuit.

[0043] In use, electron emitters 208 emit narrow beams 714 of electronsonto the surface of the storage medium 210. These beams exciteelectron-hole pairs near the surface of the medium. Because storagemedium 210 is reverse-biased by the external circuit 704, the minoritycarriers that are generated by the incident electrons are swept towardthe diode junction 710. Electrons that reach the junction 710 are thenswept across the junction. Accordingly, minority carriers that do notrecombine with majority carriers before reaching the junction 710 areswept across the junction, causing a current flow in the externalcircuit 704.

[0044] As described above, writing is accomplished by increasing thepower density of electron beams enough to locally alter the physicalproperties of storage medium 210. Where the medium 210 is configured asshown in FIG. 7, this alteration affects the number of minority carriersswept across the junction 710 when the same area is radiated with alower power density “read” electron beam. For instance, therecombination rate in a written (i.e., modified) area 708 could beincreased relative to an unwritten (i.e., unmodified) area 706 so thatthe minority carriers generated in the written area have an increasedprobability of recombining with minority carriers before they have achance to reach and cross junction 710. Hence, a smaller current flowsin external circuit 604 when the “read” electron beam is incident upon awritten area 708 than when it is incident upon an unwritten area 706.Conversely, it is also possible to start with a diode structure having ahigh recombination rate and to write bits by locally reducing therecombination rate. The magnitude of the current resulting from theminority carriers depends upon the state of particular storage area, andthe current continues the output signal 712 to indicate the bit stored.

[0045] Reference will now be made to FIG. 8, which schematically depictsa representative embodiment of a storage medium 210 of a data storagedevice 200. Flexures 218, such as springs, beams or other flexiblesupport mechanisms, for example, extend from storage medium 210 andpermit movement of the storage medium in some embodiments. As shown inFIG. 8, storage medium 210 includes multiple data clusters. Inparticular, fifteen (15) such data clusters, e.g., data clusters 802,804, 806, 808, 810, 812, 814, 816, 818, 820, 822, 824, 828, and 830, areprovided on storage medium 210. In other embodiments, however, variousother numbers and configurations of data clusters can be provided. Eachdata cluster is capable of including multiple storage areas.

[0046] Each data cluster is associated with multiple electron emitters.For example, in some embodiments, over one hundred (100) emitters can beprovided in each data cluster. Preferably, only one emitter associatedwith a particular data cluster is “on,” e.g., either reading or writingdata, at any given time. Additionally, an external circuit (not shown)is associated with each data cluster that facilitates transmission ofdata from the data cluster. For instance, each external circuit caninclude an amplifier, among other various components.

[0047] A servo cluster 840 is provided upon storage medium 210. Servocluster 840 is configured to store data that is used for providingsensor feedback to a servo system (not shown). The servo system readsinformation from the servo cluster and uses the information to positionthe storage medium and emitters relative to the other.

[0048] In FIG. 9, representative data clusters 802, 804, 806, and 808 ofFIG. 8 are shown in greater detail. Representative contact areas thatare configured to accommodate placement of electrical contacts and/orleads also are depicted in FIG. 9. As shown therein, contacts preferablyare provided at spaced intervals across each data cluster. Inparticular, contacts 902 are associated with data cluster 804, contacts904 are associated with data cluster 806, contacts 906 are associatedwith data cluster 814, and contacts 908 are associated with servocluster 840. Each contact, in turn, electrically communicates with acorresponding lead. More specifically, contacts 902 electricallycommunicate with lead 910, contacts 904 electrically communicate withlead 912, contacts 906 electrically communicate with lead 914, andcontacts 908 electrically communicate with lead 916. The leads can beadapted to provide electrical signals to and/or from storage areas ofthe corresponding data clusters. Contact areas 920 accommodate placementof at least some of the electrical contacts and/or leads.

[0049] Reference will now be made to FIG. 10, which depicts anembodiment of vacuum chamber 100 that can be used for assembling a datastorage device. In FIG. 10, vacuum chamber 100 includes a formation zone102 that selectively communicates with an entry lock 1010. Entry lock1010 defines an entry chamber 1012 that is adapted to receive a wafer210 for processing. The wafer is adapted to include storage media andmay be configured as a rotor wafer. Access to entry chamber 1012 isprovided by an entry mechanism 1014. Entry mechanism 1014 can be a dooror any other suitable component or combination of components that areadapted to selectively provide access to the entry lock. Entry lock 1010also includes an egress component that is adapted to selectively enableentry chamber 1012 to communicate with formation zone 102. Egresscomponent 1016 also can be a door or other suitable component(s).

[0050] Transport component(s) are provided within vacuum chamber 100.For example, transport component(s) can be adapted to facilitatetransport of one or more wafers through the various chambers and/orzones of the vacuum chamber. In FIG. 10, a separate transport componentis depicted substantially within each chamber/zone. For instance,transport component 1020 is provided in entry lock 1010. In otherembodiments, however, a particular assembly of transport componentscould facilitate transport of one or more wafers between multiplechambers and/or zones.

[0051] Formation zone 102 includes components required for formingstorage media on wafer 210. In particular, formation zone 102 caninclude media deposition component(s) 1030 and/or contact/leadapplication component(s) 1032. In some embodiments, storage media isdeposited onto wafer 210 via a vapor deposition technique. In theseembodiments, media deposition component 1030 includes one or moredeposition material receptacles (not shown) that are adapted to store anamount of deposition material that will be required to complete thestorage media deposition process. Each receptacle can be selectivelyprovided within the formation zone so that material contained within thereceptacle can be appropriately vaporized and applied to wafer 210.

[0052] Prior to being provided within formation zone 102, wafer 210 canbe appropriately masked. Masking of the wafer will prevent deposition ofmaterial at other than unmasked locations of the wafer. In otherembodiments, components that are adapted to facilitate masking of wafer210 within the formation zone can be provided within vacuum chamber 100.

[0053] Once material, e.g., storage media, has been deposited upon thewafer, various other wafer processing can occur. For example,contact/lead application components 1032 can apply one or more contactsand/or one or more leads to the wafer. A representative arrangement ofstorage media, contacts and leads was depicted in FIG. 9.

[0054] After applicable wafer processing has been completed within theformation zone, the wafer can be transported, such as via transportcomponent 1034, from the formation zone to an intermediate zone 1040. Asdepicted in FIG. 10, intermediate zone 1040 is arranged betweenformation zone 102 and assembly zone 104. In this embodiment, theintermediate zone selectively communicates with each zone andeffectively isolates contaminants that may be contained in the formationzone from entering the assembly zone. Selective communication of theintermediate zone with the formation zone is facilitated by an entrymechanism 1042, e.g., a door. Thus, after processing within formationzone 102, wafer 210 can be transported into intermediate zone 1040through operation of entry mechanism 1042.

[0055] Upon entering the intermediate zone, entry mechanism 1042 closesto isolate the formation zone from the intermediate zone. By so doing,contaminants contained in the formation zone may be removed, such as byaction of vacuum components 1050. Vacuum components 1050 can communicatewith one or more of the various zones and/or chambers of the vacuumchamber 100 to selectively maintain a vacuum within one or more of thezones and/or chambers. By providing the vacuum, contaminants also candrawn from the formation zone. This could include deposition materialthat did not deposit upon wafer 210.

[0056] Wafer 210 can be transported from the intermediate zone bytransport component(s) 1052. An egress mechanism 1054 enables theintermediate zone to selectively communicate with assembly zone 104.Thus, wafer 210 is able to enter the assembly zone when the egressmechanism, e.g., a door, is in its open position.

[0057] Assembly zone 104 includes alignment/sealing component(s) 1060that are adapted to align wafer 210 and 202 and seal the wafers togetherso that a vacuum is maintained within one or more chambers definedbetween the wafers. Once appropriate sealed, transport component 1062can deliver the sealed wafers (wafer stack) to a chamber 1070 defined byexit lock 1072. Access to chamber 1070 is selectively provided by anentry mechanism 1074, e.g., a door, when the entry mechanism is in itsopen position. Once positioned within chamber 1070, the entry mechanismcan close, thereby maintaining the vacuum within at least a portion ofchamber 100. Access to the wafer stack positioned within chamber 1070 isprovided by an egress mechanism 1076. Transport component(s) 1080 can beused to promote removal of the wafer stack from chamber 100.

[0058] Embodiments of the vacuum assembly system can facilitateautomatic formation and assembly of wafer stacks. In these embodiments,a control system, such as control system 1100 (FIG. 11), can beutilized. In FIG. 11, control system 1100 electrically communicates withvarious components of the vacuum assembly system. More specifically,control system 1100 communicates with one or more of entry mechanism1014, egress mechanism 1016, media deposition component(s) 1030,contact/lead application component(s) 1032, entry mechanism 1042, egressmechanism 1054, vacuum component 1050, alignment/sealing component 1060,entry mechanism 1075, egress mechanism 1076, and one or more of variouscontrol components. Additionally, control system 1100 can communicatewith one or more sensors 1110. More specifically, a sensor 1110 can beadapted to sense the vacuum pressure within one or more zones and/orchambers of vacuum chamber 100 and provide a corresponding signal to thecontrol system. So provided, information provided by sensor 1100 can beused by the control system to operate the vacuum components formaintaining the vacuum within the chamber 100 at a suitable level.

[0059] Control system 1100 can be implemented in software, firmware,hardware, or a combination thereof. When implemented in hardware, thecontrol system can be implemented with any or a combination of varioustechnologies. By way of example, the following technologies, which areeach well known in the art, can be used: a discrete logic circuit(s)having logic gates for implementing logic functions upon data signals,an application specific integrated circuit (ASIC) having appropriatecombinational logic gates, a programmable gate array(s) (PGA), and afield programmable gate array (FPGA).

[0060] In an alternative embodiment, the control system 1100 isimplemented in software as an executable program. The control system canbe executed by a special or general purpose digital computer, such as apersonal computer (PC; IBM-compatible, Apple-compatible, or otherwise),workstation, minicomputer, or mainframe computer. An example of ageneral purpose computer that can implement the control system is shownschematically in FIG. 12.

[0061] Generally, in terms of hardware architecture, computer 1200includes a processor 1202, memory 1204, and one or more input and/oroutput (I/O) devices 1206 (or peripherals) that are communicativelycoupled via a local interface 1208. Local interface 1208 can be, forexample, one or more buses or other wired or wireless connections, as isknown in the art. Local interface 1208 can include additional elements,which are omitted for ease of description. These additional elements canbe controllers, buffers (caches), drivers, repeaters, and/or receivers,for example. Further, the local interface may include address, control,and/or data connections to enable appropriate communications among thecomponents of computer 1200.

[0062] Processor 1202 is a hardware device configured to executesoftware that can be stored in memory 1204. Processor 1202 can be anycustom made or commercially avail-able processor, a central processingunit (CPU) or an auxiliary processor among several processors associatedwith the computer 1200. Additionally, the processor can be asemi-conductor-based microprocessor (in the form of a microchip) or amacroprocessor. Examples of representative commercially availablemicroprocessors are as follows: a PA-RISC series microprocessor fromHewlett-Packard Company, U.S.A., an 80×86 or Pentium seriesmicroprocessor from Intel Corporation, U.S.A., a PowerPC microprocessorfrom IBM, U.S.A., a Sparc microprocessor from Sun Microsystems, Inc, ora 68control series microprocessor from Motorola Corporation, U.S.A.

[0063] Memory 1204 can include any combination of volatile memoryelements (e.g., random access memory (RAM, such as DRAM, SRAM, etc.))and/or nonvolatile memory elements (e.g., ROM, hard drive, tape, CDROM,etc.). Moreover, memory 1204 can incorporate electronic, magnetic,optical, and/or other types of storage media. Note that memory 1204 canhave a distributed architecture, where various components are situatedremote from one another, but can be accessed by processor 1202.

[0064] The software in memory 1204 can include one or more separateprograms, each of which comprises an ordered listing of executableinstructions for implementing logical functions. In the example of FIG.11, the software in the memory 1204 includes the control system 1100 anda suitable operating system (O/S) 1210. A nonexhaustive list of examplesof commercially available operating systems 1210 is as follows: aWindows operating system from Microsoft Corporation, U.S.A., a Netwareoperating system available from Novell, Inc., U.S.A., or a UNIXoperating system, which is available for purchase from many vendors,such as Hewlett-Packard Company, U.S.A., Sun Microsystems, Inc., andAT&T Corporation, U.S.A. The operating system 1210 controls theexecution of other computer programs, such as the control system 1100.Operating system 1210 also provides scheduling, input-output control,file and data management, memory management, and communication controland related services.

[0065] The I/O device(s) 1206 can include input devices such as akeyboard, for example. I/O device(s) 1206 also can include outputdevices such as a display, for example. I/O device(s) 1206 may furtherinclude devices that are configured to communicate both inputs andoutputs such as a modulator/demodulator, for example.

[0066] When the computer 1200 is in operation, processor 1202 isconfigured to execute software stored within the memory 1204,communicate data to and from the memory 1204, and generally controloperations of the computer 1200. The control system 1100 and the O/S1210, in whole or in part, are read by the processor 1202, perhapsbuffered within processor 1202, and then executed.

[0067] When control system 1100 is implemented in software, it should benoted that the control system can be stored on any computer readablemedium for use by or in connection with any computer-related system ormethod. In the context of this document, a computer-readable medium isan electronic, magnetic, optical, or other physical device or means thatcan contain or store a computer program for use by or in connection witha computer-related system or method. Control system 1100 can be embodiedin any computer-readable medium for use by or in connection with aninstruction execution system, apparatus, or device, such as acomputer-based system, processor-containing system, or other system thatcan fetch the instructions from the instruction execution system,apparatus, or device and execute the instructions.

[0068] In the context of this document, a “computer-readable medium” canbe any means that can store, communicate, propagate, or transport theprogram for use by or in connection with the instruction executionsystem, apparatus, or device. The computer readable medium can be, forexample but not limited to, an electronic, magnetic, optical,electromagnetic, infrared, or semiconductor system, apparatus, device,or propagation medium. More specific examples (a nonexhaustive list) ofthe computer-readable medium would include the following: an electricalconnection (electronic) having one or more wires, a portable computerdiskette (magnetic), a random access memory (RAM) (electronic), aread-only memory (ROM) (electronic), an erasable programmable read-onlymemory (EPROM, EEPROM, or Flash memory) (electronic), an optical fiber(optical), and a portable compact disc read-only memory (CDROM)(optical). Note that the computer-readable medium could even be paper oranother suitable medium upon which the program Is printed, as theprogram can be electronically captured, via for instance opticalscanning of the paper or other medium, then compiled, interpreted orotherwise processed in a suitable manner if necessary, and then storedin a computer memory.

[0069] The flowchart of FIG. 13 shows the functionality of animplementation of the control system. In this regard, each block of theflowchart represents a module segment or portion of code which comprisesone or more executable instructions for implementing the specifiedlogical function or functions. It should also be noted that in somealternative implementations, the functions noted in the various blocksmay occur out of the order depicted in FIG. 13. For example, two blocksshown in succession in FIG. 13 may, in fact, be executed substantiallyconcurrently where the blocks may sometimes be executed in the reverseorder depending upon the functionality involved. In this regard, thecontrol system or method 1100 of FIG. 13 may be construed as beginningat block 1305 where access to the entry lock is enabled. Morespecifically, the control system can send a signal to the entrymechanism that prompts the entry mechanism to move to its open position.In block 1310, transport of the wafer into the formation zone isenabled. In some embodiments, this can include providing a signal totransport component 1020 so that the wafer is transported from the entrylock into the formation zone. In those embodiments incorporating anegress mechanism 1016, a signal also can be sent to the egress entrymechanism to ensure that the egress mechanism is in its open position.This can enable the wafer to be transported from the entry lock into theformation zone.

[0070] In block 1315, formation of a vacuum within one or more chambersand/or zones of the vacuum chamber 100 is enabled. In some embodiments,this can include ensuring that the egress mechanism 1016 is in itsclosed position. Once a suitable vacuum has been established within theformation zone, the process may proceed to block 1320 where formation ofstorage media is enabled. As mentioned hereinbefore, this can includeproviding material in an appropriate arrangement within the formationzone so that vapor deposition of the material can be carried out. Inblock 1325, a determination may be made as to whether formation of thestorage media is complete. If it is determined that the formation is notcomplete, the process may return to block 1320 and the formation processcan be continued until complete. Upon completion, the process mayproceed to block 1330 where the application of more or more contactsand/or one or more leads to the storage media is enabled. In block 1335,a determination then can be made as to whether the application processis complete. If it is determined that application of one or morecontacts and/or one or more leads is not complete, the process mayreturn to block 1330 until completion. Upon completion, the process mayproceed to block 1340 where isolation of deposition materials is enabledwithin the formation zone. More specifically, further wafer processingmay be discontinued until contaminants are removed from the formationzone, such as by vacuum components. In other embodiments, the wafer maybe transported to the intermediate zone and contained therein untilcontaminants are removed.

[0071] Once contaminants are appropriately removed from one or morezones and/or chambers of the vacuum chamber, the wafer can betransported into the assembly zone. Thereafter, alignment of a rotorwafer with the stator wafer is enabled (block 1350). In block 1355, thewafers are sealed together to form a wafer stack. As mentionedhereinbefore, maintenance of the vacuum within the assembly zone permitsthe wafers to be sealed together while maintaining an interior chamberof the wafer stack under vacuum. Proceeding to block 1360, adetermination may be made as to whether the assembly process iscomplete. If it is determined that the process is not complete, theprocess may return to block 1355 until completion. If, however, assemblyis complete, the process may proceed to block 1365 where transport ofthe wafer stack from the assembly zone is enabled. In block 1370, accessto the assembled wafer stack is provided, such as providing access tothe wafer via the exit lock.

[0072] The foregoing description has been presented for purposes ofillustration and description. It is not intended to be exhaustive or tolimit the invention to the precise forms disclosed. Modifications orvariations are possible in light of the above teachings. The embodimentor embodiments discussed, however, were chosen and described to providethe best illustration of the principles of the invention and itspractical, application to thereby enable one of ordinary skill in theart to utilize the invention in various embodiments and with variousmodifications as are suited to the particular use contemplated. All suchmodifications and variations, are within the scope of the invention asdetermined by the appended claims when interpreted in accordance withthe breadth to which they are fairly and legally entitled.

What is claimed is:
 1. A system for assembling a wafer stack, the waferstack being adapted to form a data storage device, the wafer stackincluding a first wafer and a second wafer, the first wafer and secondwafer defining therebetween an interior chamber, said system comprising:a vacuum chamber; a media deposition component arranged within saidvacuum chamber, said medium deposition component being configured todeposit storage media upon the first wafer; and a wafer stack assemblycomponent arranged within said vacuum chamber, said wafer stack assemblycomponent being configured to align the first wafer and a second waferrelative to each other and bond the first wafer and the second wafertogether while at least a portion of said vacuum chamber is maintainedunder vacuum pressure such that the interior chamber of the wafer stackis maintained under vacuum pressure.
 2. The system of claim 1, whereinsaid vacuum chamber defines a media deposition zone and a wafer stackassembly zone, said vacuum chamber being adapted to place at least oneof said media deposition zone and said wafer stack assembly zone undervacuum pressure, said media deposition zone being configured to receivethe first wafer, said media deposition component being arranged withinsaid media deposition zone.
 3. The system of claim 1, furthercomprising: a vacuum component pneumatically communicating with saidvacuum chamber, said vacuum component being adapted to maintain at leasta portion of said vacuum chamber under vacuum pressure; and a controlsystem electrically communicating with said vacuum component, saidcontrol system being adapted to provide a control signal to said vacuumcomponent such that, in response thereto, said vacuum componentmaintains the pressure within a least a portion of said vacuum chamberat a selected pressure.
 4. The system of claim 2, wherein said waferstack assembly component is arranged within said wafer stack assemblyzone.
 5. The system of claim 2, further comprising: a transportcomponent arranged within said vacuum chamber, said transport componentbeing adapted to transport the first wafer from said media depositionzone to said wafer stack assembly zone.
 6. The system of claim 2,further comprising: an entry lock configured to selectively communicatewith said media deposition zone, said entry lock being adapted toreceive the first wafer and facilitate delivery of the first wafer tosaid media deposition zone.
 7. The system of claim 2, furthercomprising: means for facilitating delivery of the first wafer to saidmedia deposition zone.
 8. The system of claim 3, wherein said vacuumcomponent is adapted to maintain at least a portion of said vacuumchamber at a pressure as low as approximately 10⁻⁸ Torr.
 9. The systemof claim 3, further comprising: a transport component arranged withinsaid vacuum chamber, said transport component being adapted to transportthe first wafer from said media deposition zone to said wafer stackassembly zone; and wherein said control system is configured to enablesaid media deposition component to deposit storage media automaticallyupon the first wafer, enable said transport component to transport thefirst wafer to said wafer stack assembly zone, and enable said waferstack assembly component to align the first wafer and a second waferrelative to each other and bond the first wafer and the second wafertogether while said vacuum component maintains said wafer stack assemblyzone under vacuum pressure.
 10. A method for forming a data storagedevice comprising: providing a first wafer and a second wafer, the firstwafer and second wafer being configured to define therebetween aninterior chamber; maintaining the first wafer under vacuum pressure;depositing storage media upon the first wafer; removing contaminantsfrom a vicinity of the first wafer; and bonding the first wafer and thesecond wafer together to form a wafer stack such that the interiorchamber is maintained under vacuum pressure after the first wafer andsecond wafer are bonded together.
 11. The method of claim 10, furthercomprising: providing a vacuum chamber; and placing the first waferwithin the vacuum chamber; and wherein the first wafer is maintainedunder vacuum pressure within the vacuum chamber.
 12. The method of claim11, wherein at least some of the contaminants are removed from thevicinity of the first wafer by the vacuum chamber.
 13. The method ofclaim 11, wherein the vacuum chamber defines a first zone; and whereinthe storage media is deposited upon the first wafer within the firstzone.
 14. The method of claim 11, further comprising: applying at leastone of a contact and a lead to the first wafer after the storage mediais deposited upon the first wafer.
 15. The method of claim 11, whereinthe first wafer is maintained under a first vacuum pressure as the firstwafer and the second wafer are bonded together to form the wafer stack,the first vacuum pressure corresponding to a vacuum pressure to bemaintained in the interior chamber of the wafer stack.
 16. The method ofclaim 11, wherein some of the contaminants are removed from the vicinityof the first wafer by transporting the first wafer out of the firstzone.
 17. The method of claim 12, wherein the vacuum chamber defines asecond zone separated from the first zone; and further comprising:transporting the first wafer from the first zone to the second zoneafter the storage media is deposited upon the first wafer.
 18. Themethod of claim 13, further comprising: providing a first chamberselectively pneumatically communicating with the first zone such that,when the first chamber is not pneumatically communicating with the firstzone, the first wafer can be placed in the first chamber, and when thefirst chamber is pneumatically communicating with the first zone, thefirst wafer can be transported from the first chamber and into the firstzone.
 19. The method of claim 14, wherein the vacuum chamber defines asecond zone separated from the first zone; and further comprising:transporting the first wafer from the first zone to the second zoneafter at least one of a contact and a lead is applied to the firstwafer.
 20. The method of claim 17, further comprising: providing asecond chamber selectively pneumatically communicating with the secondzone such that, when the second chamber is pneumatically communicatingwith the second zone, the wafer can be transported from the second zoneand into the second chamber, and when the second chamber is notpneumatically communicating with the second zone, the wafer stack can beremoved from the second chamber.